An acoustic resonator has a piezoelectric plate attached to the surface of the substrate except for a portion of the piezoelectric plate forming a diaphragm spanning a cavity in the substrate. An interdigital transducer (IDT) formed on the plate has interleaved fingers on the diaphragm with first parallel fingers extending from a first busbar and second parallel fingers extending from a second busbar of the IDT. The first and second busbars of the IDT terminate in beveled corners that extend off of the diaphragm as side edges of the busbars that form angles with a perimeter of the cavity.

An acoustic wave filter device includes a base having an acoustic wave filter part and a bonding part disposed thereon, the bonding part surrounding the acoustic wave filter part, and a cap having a bonding counterpart disposed thereon, the bonding counterpart being bonded to the bonding part of the base, and the bonding part includes a first bonding layer including gold, and the bonding counterpart includes a second bonding layer bonded to the first bonding layer and including tin.

An acoustic wave filter device includes a base having an acoustic wave filter part and a bonding part disposed thereon, the bonding part surrounding the acoustic wave filter part, and a cap having a bonding counterpart disposed thereon, the bonding counterpart being bonded to the bonding part of the base, and the bonding part includes a first bonding layer including gold, and the bonding counterpart includes a second bonding layer bonded to the first bonding layer and including tin.

Embodiments of a Surface Acoustic Wave (SAW) device and methods of fabrication thereof are disclosed. In some embodiments, a SAW device includes a quartz carrier substrate, a piezoelectric layer on a surface of the quartz carrier substrate, and at least one interdigitated transducer on a surface of the piezoelectric layer opposite the quartz carrier substrate, wherein a thickness of the piezoelectric layer is less than twice a transducer electrode period of the at least one interdigitated transducer. Using the piezoelectric layer on the carrier substrate suppresses acoustic radiation into the bulk, thereby improving the performance of the SAW device. Further, by utilizing quartz for the carrier substrate, additional advantages of small viscous losses, small permittivity, and small thermal sensitivity are achieved. Still further, as compared to Silicon, the use of quartz for the carrier substrate eliminates resistive losses.

A filter device includes first and second filters respectively having first and second passbands, the second passband being in a frequency range higher than the first passband. The first and second filters are commonly connected to a common terminal. In the first filter, multiple parallel arm resonators define a parallel connection unit in which the parallel arm resonators are connected in parallel with no serial arm resonators interposed therebetween. The parallel arm resonators in the parallel connection unit include first and second parallel arm resonators having anti-resonant frequencies different from each other. In combined impedance-frequency characteristics of the parallel arm resonators in the parallel connection unit, at least one anti-resonant frequency other than a highest anti-resonant frequency is equal to or higher than 2f.sub.1min−f.sub.2min and equal to or lower than 2f.sub.1max−f.sub.2max.

Disclosed are a patterned substrate, a semiconductor device and a nanotube structure. The patterned substrate includes, in a vertical direction, a base plate and an AlN layer that are sequentially stacked. The patterned substrate includes, in the vertical direction, a first surface and a second surface that are oppositely arranged, a bottom surface of the base plate is the first surface of the patterned substrate, the second surface of the patterned substrate is a patterned surface, the second surface is provided with a plurality of grooves that are independent of each other in a horizontal direction and are arranged in an array, and at least part of the base plate is left below each of the plurality of grooves. According to the patterned substrate in the present application, a structure of the AlN layer is changed, so that an epitaxial structure grown subsequently is prevented from warping.

A duplexer includes: a transmit filter connected between a transmit terminal and an antenna terminal and including series resonators and parallel resonators connected in a ladder form; and a receive filter connected between a receive terminal and the antenna terminal, wherein at least one of resonators, which are resonators other than a first series resonator and a first parallel resonator located at a first stage as viewed from a side of the transmit terminal and a second series resonator and a second parallel resonator located at a first stage as viewed from a side of the antenna terminal and have electrostatic capacitances less than an electrostatic capacitance of at least one of the first series resonator, the first parallel resonator, the second series resonator, and the second parallel resonator in the series resonators and the parallel resonators, is divided in series.

A bulk acoustic resonator includes: a substrate including an upper surface on which a substrate protection layer is disposed; and a membrane layer forming a cavity together with the substrate, wherein a thickness deviation of either one or both of the substrate protection layer and the membrane layer is 170 Å or less.

Aspects of this disclosure relate to bulk acoustic wave components. A bulk acoustic wave component can include a substrate, at least one bulk acoustic wave resonator on the substrate, and a cap enclosing the at least one bulk acoustic wave resonator. The cap can include a sidewall spaced apart from an edge of the substrate. The sidewall can be 5 microns or less from the edge of the substrate.

Acoustic resonator devices, filter devices, and methods of fabrication are disclosed. A resonator device includes a single-crystal piezoelectric plate having a front surface and a back surface opposite the front surface, wherein the back surface is coupled to a surface of a substrate. A floating back-side conductor pattern is formed on a portion of the back surface. A front-side conductor pattern including two electrodes is formed on a portion of the front surface opposite the back-side conductor.